<template>
  <div id="app">
    <router-view></router-view>
  </div>
</template>

<script>
export default {
  name: "app",
  created() {
    //在页面加载时读取sessionStorage里的状态信息
    if (sessionStorage.getItem("store")) {
      this.$store.replaceState(
          Object.assign(
              {},
              this.$store.state,
              JSON.parse(sessionStorage.getItem("store"))
          )
      );
    }
    //在页面刷新时将vuex里的信息保存到sessionStorage里
    window.addEventListener("beforeunload", () => {
      sessionStorage.setItem("store", "");
      sessionStorage.setItem("store", JSON.stringify(this.$store.state));
    });
  }
};
</script>

<style>

</style>
